<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

    <div id="app">
        <h2>{{ msg }}</h2>
        <button @click="fn()">逆转世界</button>
    </div>

    <script src="../js/vue.js"></script>
    <script>
        const app = new Vue({
            el: '#app',
            data: {
                msg: 'Hello World'
            },
            methods: {
                fn() {
                    this.msg = this.msg.split('').reverse().join('')
                }
            }
        })
    </script>


</body>

</html>